Unable to connect to ps7_cortexa9的参考解决方案Zedboard,zynq

Unable to connect to ps7_cortexa9

JTAG: cannot shift DR

This problem appears when the connection between arm cortex a9 and computer is broken. We have no effective solution to solve the problem. You can refer the following several operations to get the trouble away.

1. Select Xilinx Tools>XMD Console, type the command: connect arm hw in the XMD console View, some status message will transformed from the cortex core. The message is shown as follows:

   XMD% connect arm hw

    

   --------------------------------------------------

   Enabling extended memory access checks for Zynq.

   Writes to reserved memory are not permitted and reads return 0.

   To disable this feature, run "debugconfig -memory_access_check disable".

    

   --------------------------------------------------

    

   CortexA9 Processor Configuration

   -------------------------------------

   Version.............................0x00000003

   User ID.............................0x00000000

   No of PC Breakpoints................6

   No of Addr/Data Watchpoints.........1

    

   Connected to "arm" target. id = 64

   Starting GDB server for "arm" target (id = 64) at TCP port no 1234

    But once the zedboard is not connected normally with the pc, the message appears different from above.

1. Exit Xilinx SDK->Switch off zedboard->Switch On Zedboard->Start Xilinx SDK, try it!
2. Restart Windows.
3. Power off the Computer and switch off zedboard, pull out the use cable and have a rest. God Help! Then go on trying it!